Tightwad Posted March 31, 2011 Share Posted March 31, 2011 The battery consists of 4 cells, each of them reading 3.43-3.44 volts. Adds up to 13.74 resting (before ever connecting to the bike) There have been a number of topics regarding those who have been installing LiFePO4 batteries. MOTY sells one based on the A123 cells, others sell them in cases that look like a regular motorcycle battery. I needed a new battery as mine had a bad cell from the beginning, so I decided to build my own. Most LiFePO4 batteries I have seen either mis-state their actual power/capacity, or understate the need for more...and I like more! The Headway cells I used are rated at 10AH...MOTY is 4.6 AH for their 8-cell battery. The weight of the MOTY is 1/2 the weight of the one I built, and smaller in size as well. I was actually quite please with the size of mine...in fact I was nervous it wouldn't fit. Completed unit: My battery compared to the Yuasa I removed (bad cell from the beginning I think): Battery weight...less than 1/2 the Yuasa: The non-critical end....I taped a piece of plexiglass over it to avoid anything shorting out the cells: The business end...I bolted an Anderson Powerpole connector in to facilitate removal/install of the battery: Installed in the bike...so easy a caveman could do it: With the cover in place, you almost can't tell: Link to comment Share on other sites More sharing options...
Member Contributer digitallyhip Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted March 31, 2011 Share Posted March 31, 2011 dare we ask the cost? Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 NICE Makes sure you watch your instrument lights at night and see if you have any flickering . When I install the MOTY I notice it. I change it out and install a new R\R so I do not know what cause it for sure !!!!!!!!!! P.S. Dont put that in your carry bags !!!!!!!!!!! Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 Doesn't it need charge control circuitry??? Link to comment Share on other sites More sharing options...
Member Contributer TheBigCheese Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 So you don't need a special charging circuit with LiFePO4? That sure makes things easier. Link to comment Share on other sites More sharing options...
Tightwad Posted March 31, 2011 Author Share Posted March 31, 2011 As long as the charging voltage stays below ~14.8volts, there SHOULD be no problems. With the open cell design I can monitor the individual cells to be sure they stay in balance. In the event that they begin to drift apart, a single cell charger can be used to correct the errant cell. Max voltage for any one cell should be kept under 3.7 volts. There is a valid argument for installing a balancing circuit, but I haven't yet seen a motorcycle battery with this kind of circuitry in use. Obviously with electric vehicles that have hundreds of cells it becomes a bigger issue and harder to manage. I would love to design a 4 channel voltmeter that would show each cell voltage without taking the seat off....possibly that will come in the future if I find the time to figure it out. Link to comment Share on other sites More sharing options...
Member Contributer 2thdr Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 I sure admire your inventiveness Link to comment Share on other sites More sharing options...
Member Contributer VFRwhisp Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 Looks like tightwad may be adding a LiFePO4 alternative to his list of "must haves" for you bike :) Link to comment Share on other sites More sharing options...
Member Contributer dutchinterceptor Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 Why does this not surprise me? Well done Joshua! Link to comment Share on other sites More sharing options...
Tightwad Posted March 31, 2011 Author Share Posted March 31, 2011 Looks like tightwad may be adding a LiFePO4 alternative to his list of "must haves" for you bike :) Not sure if this will make the lineup....I would like to do more testing (possibly limited sales for more test data) before I stand behind them as a good mod. I am going to hook my heated gear up with the bike not running to see how much it can take....I made the mistake of leaving my gear on once and had to push-start my bike (Thanks Dutch!). Link to comment Share on other sites More sharing options...
Member Contributer CHUCK2 Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 Very Nice-Nice, Joshua. Now, this is something I can honestly say that you're the inventor of! What does LiFePO4 stand for anyway? Link to comment Share on other sites More sharing options...
Tightwad Posted March 31, 2011 Author Share Posted March 31, 2011 Very Nice-Nice, Joshua. Now, this is something I can honestly say that you're the inventor of! What does LiFePO4 stand for anyway? Not sure I can claim the inventor on this either...I really just assembled it. You can order the parts to make your own from www.headway-headquarters.com. Requires 4 cells, 3 buss bars, 4 holders ($134.74 with shipping). Also required is the 8 gauge Powerpole connectors (requires a set of 2). I also used 4 of the 8 gauge copper lugs with 1/4" hole and 8 gauge wire. The plexiglass on the end was for my own piece of mind, especially as I was working with this on my cluttered workbench and didn't want to short it out. This can be built for a total of about $150 I would guess, plus your labor to build it (actually pretty easy, other than the Powerpole crimping/heat shrink part which isn't hard). LiFePO4 stands for "Lithium iron phosphate" Link to comment Share on other sites More sharing options...
Member Contributer CHUCK2 Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 Ugg.Maybe one of these times I'll get it right. Ok..assembler then. Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 Very Nice-Nice, Joshua. Now, this is something I can honestly say that you're the inventor of! What does LiFePO4 stand for anyway? Not sure I can claim the inventor on this either...I really just assembled it. You can order the parts to make your own from www.headway-headquarters.com. Requires 4 cells, 3 buss bars, 4 holders ($134.74 with shipping). Also required is the 8 gauge Powerpole connectors (requires a set of 2). I also used 4 of the 8 gauge copper lugs with 1/4" hole and 8 gauge wire. The plexiglass on the end was for my own piece of mind, especially as I was working with this on my cluttered workbench and didn't want to short it out. This can be built for a total of about $150 I would guess, plus your labor to build it (actually pretty easy, other than the Powerpole crimping/heat shrink part which isn't hard). LiFePO4 stands for "Lithium iron phosphate" I paid $370 total for the 3 MOTY's I bought! Link to comment Share on other sites More sharing options...
Tightwad Posted March 31, 2011 Author Share Posted March 31, 2011 Very Nice-Nice, Joshua. Now, this is something I can honestly say that you're the inventor of! What does LiFePO4 stand for anyway? Not sure I can claim the inventor on this either...I really just assembled it. You can order the parts to make your own from www.headway-headquarters.com. Requires 4 cells, 3 buss bars, 4 holders ($134.74 with shipping). Also required is the 8 gauge Powerpole connectors (requires a set of 2). I also used 4 of the 8 gauge copper lugs with 1/4" hole and 8 gauge wire. The plexiglass on the end was for my own piece of mind, especially as I was working with this on my cluttered workbench and didn't want to short it out. This can be built for a total of about $150 I would guess, plus your labor to build it (actually pretty easy, other than the Powerpole crimping/heat shrink part which isn't hard). LiFePO4 stands for "Lithium iron phosphate" I paid $370 total for the 3 MOTY's I bought! You save on shipping if buying 3.....$348 from Headway-Headquarters for the parts to make 3, minus the Anderson connectors and wire etc. I didn't think MOTY reduced their price on multiple purchases...I thought they just added voltmeters to them for the group buys. Link to comment Share on other sites More sharing options...
Member Contributer CHUCK2 Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 MOTY added voltmeters?? As in threw them in for free? One for each battery sold in the group buy here? Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 MOTY added voltmeters?? As in threw them in for free? One for each battery sold in the group buy here? Nope, they didn't do that. I got one of mine second hand, so didn't pay MOTY's group buy price for the third battery. Link to comment Share on other sites More sharing options...
Tightwad Posted March 31, 2011 Author Share Posted March 31, 2011 MOTY added voltmeters?? As in threw them in for free? One for each battery sold in the group buy here? The voltmeter is attached to the battery. He told me they use them as a way to offer a discount without lowering the price of the actual battery. I can't see the use of it hidden under the seat...I think it is more of a racing item for total loss systems (no charging ability). Link to comment Share on other sites More sharing options...
Member Contributer CHUCK2 Posted March 31, 2011 Member Contributer Share Posted March 31, 2011 Or perhaps when the battery is stored out of the bike on a shelf, it would make it easy to check the voltage of it. Such as during the winter months. Link to comment Share on other sites More sharing options...
Tightwad Posted April 3, 2011 Author Share Posted April 3, 2011 I had a late night in the shop finishing a batch of VFRNesses before our family left for Lubbock, TX (Destination Imagination State competition). I decided to turn the lights on and run the battery a bit to see how it handled a pretty healthy load (7-8 amps, as a guess). I was working and watching tv, and forgot about the bike until I head a buzzing/clicking sound....turned to look just in time to see the last HID flicker and go out...whups. I ran over and saw the Datel meter peter out at about 8 volts...oh crap! LiFePO4 batterys should NOT be discharged below 3 volts, and never below 2.5 or so...or you risk them coming out of balance etc. I pulled the battery, and checked each cell...sure enough, some were at 2.3 and others at 2.6. I figured this would be a great opportunity to observe how they handled being recharged without a BMS or charging each cell separately. After 30 minutes on a 2 amp charger, they were back to over 3 volts, and perfectly balanced again (within .01 volts anyway). I did discover my multimeter is pretty shot as it was reading funny, luckily I had a Harbor Freight special to cross check with...time to invest in more tools. Link to comment Share on other sites More sharing options...
Member Contributer kaldek Posted April 3, 2011 Member Contributer Share Posted April 3, 2011 As long as the charging voltage stays below ~14.8volts, there SHOULD be no problems. With the open cell design I can monitor the individual cells to be sure they stay in balance. In the event that they begin to drift apart, a single cell charger can be used to correct the errant cell. Max voltage for any one cell should be kept under 3.7 volts. There is a valid argument for installing a balancing circuit, but I haven't yet seen a motorcycle battery with this kind of circuitry in use. Obviously with electric vehicles that have hundreds of cells it becomes a bigger issue and harder to manage. I would love to design a 4 channel voltmeter that would show each cell voltage without taking the seat off....possibly that will come in the future if I find the time to figure it out. Thanks mate. But on the topic of cell balancing, just buy a cheap charger designed for the R/C hobby industry! I have two of these things and they will do charging, balancing, discharging and everything, all for like $30! They support LiFePO4, LiPo, NiCd, NiMh, and Lead Acid. This is the bad boy you want! http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15167 And as for multi-cell voltage monitors, the hobby industry is also your friend!!! http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10952 These are just one of the options for each type of device. HobbyKing is the best freakin' website, they have *everything* electrical. Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted April 3, 2011 Member Contributer Share Posted April 3, 2011 But on the topic of cell balancing, just buy a cheap charger designed for the R/C hobby industry! I have two of these things and they will do charging, balancing, discharging and everything, all for like $30! They support LiFePO4, LiPo, NiCd, NiMh, and Lead Acid. This is the bad boy you want! http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15167 And as for multi-cell voltage monitors, the hobby industry is also your friend!!! http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10952 These are just one of the options for each type of device. HobbyKing is the best freakin' website, they have *everything* electrical. That'll work on the MOTY, as is? Just attach at the terminals like a standard charger? Edit: that one says up to 6 cells, so no good for MOTY I'm guessing... This one says up to 8 cells, so this is what I would want? Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted April 3, 2011 Member Contributer Share Posted April 3, 2011 Nice mod Josh. A little bit suprised you haven't already done the DeWalt battery pack hack. Still not entirely sure that it's safe to have LiPos or LiFePos under constant charge. Plan to run my bike lossless, and just use the battery if I'm in a pinch. However, I wonder if they have things like battery separators, where if it reads the battery at a certain voltage, it won't send any charge to them, but will allow power to be drawn. That is to say, if a separator would work in this setup. Probably would still want to check that the cells are balanced every so often. Link to comment Share on other sites More sharing options...
Tightwad Posted April 3, 2011 Author Share Posted April 3, 2011 But on the topic of cell balancing, just buy a cheap charger designed for the R/C hobby industry! I have two of these things and they will do charging, balancing, discharging and everything, all for like $30! They support LiFePO4, LiPo, NiCd, NiMh, and Lead Acid. This is the bad boy you want! http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15167 And as for multi-cell voltage monitors, the hobby industry is also your friend!!! http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10952 These are just one of the options for each type of device. HobbyKing is the best freakin' website, they have *everything* electrical. That'll work on the MOTY, as is? Just attach at the terminals like a standard charger? Edit: that one says up to 6 cells, so no good for MOTY I'm guessing... This one says up to 8 cells, so this is what I would want? The MOTY is 4s2p...so a 4 cell charger would work. the cells in parallel will self balance to each other, then you balance the 4 sets as well. I don't see any charging ports on the MOTY, so accessing the sets of cells isn't going to be possible. Link to comment Share on other sites More sharing options...
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